Toilet overflow prevention device

ABSTRACT

A toilet overflow prevention device including an overflow valve assembly, a control valve and a water level sensor. The overflow valve assembly is configured to selectively permit a flow of water through the valve assembly from the tank to the bowl of an associated toilet. The water level sensor is configured to provide a control signal in response to detecting an above-normal water level within the bowl of the toilet. The control valve is configured to actuate the overflow valve assembly in response to a control signal from the water level sensor. Preferably, the overflow valve assembly is separate from the primary flush valve of the toilet and is located between the primary flush valve and the bowl of the toilet.

RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 10/739,795, filed Dec. 18, 2003, now U.S. Pat. No. 6,961,966,the entirety of which is hereby incorporated by reference herein andmade a part of this disclosure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to toilet systems and, moreparticularly, to overflow prevention devices for toilets.

2. Description of the Related Art

Although significant advances have been made in toilet technology,particularly in reducing the amount of water needed for flushingpurposes, a satisfactory solution for preventing the overflow of atoilet in the event of a blockage of the toilet bowl, or associatedwaste plumbing, has not been achieved.

Prior art overflow prevention arrangements have tended to be complex andoften require a customized toilet design or significant modification ofa standard toilet. For example, as disclosed in U.S. Pat. No. 6,052,841,one prior art solution utilizes a water level sensor and an electricmotor to close a valve thereby preventing a flow of water from thetoilet tank to the bowl in response to an above-normal water level. Suchan arrangement is relatively expensive and requires an external sourceof power to operate the motor. In addition, such an arrangement may beunreliable, especially if the source of power is expendable, such asbatteries, for instance.

Another prior art arrangement, disclosed in U.S. Pat. No. 4,170,049,utilizes a water level sensor in the form of a float to sense anabove-normal water level. The float is connected to a stop that isconfigured to move with the float. The stop moves to a position tendingto contact the standard toilet flush valve, or flapper valve, when thefloat detects an above-normal water level, thereby inhibiting opening ofthe flush valve. Although such an arrangement eliminates the need forexternal power, the closure force acting on the flapper valve is limitedto the force that is developed by the float. Accordingly, it may bepossible for a user to overcome the closure force provided by the stopby forcefully manipulating the toilet handle. In addition, such anarrangement requires a lever assembly to operatively connect the floatwith the stop member, which results in an undesirably complex device.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention operate to prevent toiletoverflow in a cost-effective and reliable manner. In addition, preferredembodiments may be integrated into a toilet assembly during manufactureor retrofitted into an existing toilet, preferably with little or nomodification of the standard toilet. Embodiments intended forretrofitting in existing toilets preferably require a low level of skillto install.

A preferred embodiment of the present invention involves a toiletoverflow prevention device comprising an overflow valve assembly havinga secondary valve, a fluid cylinder and a transmission mechanism. Thesecondary valve is positioned between a primary flush valve of thetoilet and a bowl of the toilet. The secondary valve is configured to berotatable from an open position, wherein water is permitted to flowthrough the secondary valve, to a closed position, wherein water issubstantially prevented from flowing from a tank of the toilet to thebowl. The fluid cylinder includes a cylinder member defining a bore anda piston. The piston is configured for translation within the bore anddefines a variable volume fluid chamber with the cylinder member. Thetransmission mechanism is configured to convert translation of thepiston into rotation of the secondary valve. The piston is movable froma relaxed position to a displaced position in response to water beingintroduced into the fluid chamber to move the secondary valve from theopen position to the closed position. The device also includes a controlvalve configured to receive a flow of supply water from a toilet watersupply source. The control valve selectively directs a portion of thesupply water to the fluid chamber. The control valve is movable betweena normal position and an overflow position. In the normal position,substantially no water is directed to the fluid chamber and in theoverflow position, supply water is directed to the fluid chamber. Thedevice further includes a water level sensor configured to sense anabove-normal water level in the bowl of the toilet. In response to anabove-normal water level, the control valve is moved from the normalposition to the overflow position, thereby moving the secondary valvefrom the open position to the closed position and preventing water fromflowing from the tank into the bowl.

Another embodiment of the present invention involves a toilet overflowprevention device for use with a toilet having a tank, a bowl, a passageconnecting the tank and the bowl, and a flush valve selectivelypermitting water to move from the tank to the bowl. The device comprisesan actuator including an overflow valve having an open position, whereinwater is permitted to flow past the valve, and a closed position,wherein water is substantially prevented from flowing past the valve andinto the bowl. A water level sensor is configured to sense anabove-normal water level in the bowl of the toilet. The water levelsensor includes a main flow passage having a first end and a second end.The first end of the main flow passage is configured to receive a flowof water from a water supply source of the toilet and the second enddefines a discharge opening. The water level sensor also includes afirst branch flow passage having a first end and a second end. The firstend communicates with the main flow passage and the second end defines afirst inlet opening positioned at the above-normal water level. Thewater level sensor also includes a second branch flow passage having afirst end, a second end and a valve between the first and second ends.The first end communicates with the main flow passage and the second enddefines a second inlet opening. When the water level is below the firstinlet opening, the valve is moved to a first position and the actuatorpermits the overflow valve assembly to move to the open position. Whenthe water level is above the first inlet opening, the valve is moved toa second position and the actuator moves the overflow valve from theopen position to the closed position, thereby preventing water fromflowing from the tank into the bowl.

A preferred embodiment of a toilet overflow prevention device includesan overflow valve assembly positionable between a primary flush valve ofa toilet and the bowl of the toilet. The device comprises a water levelsensor configured to detect a water level in the toilet bowl and producea control signal in response to a water level above a predeterminedlevel. The overflow valve assembly is movable, in response to thecontrol signal, from a first position wherein water flow is permittedthrough said overflow valve to a second position wherein water flow issubstantially prevented through said valve. A preferred embodiment of atoilet overflow prevention device is a device as described immediatelyabove, wherein the control signal comprises the presence or absence of aflow of water.

Yet another preferred embodiment of a toilet overflow prevention systemincludes an overflow valve, a control valve and a water level sensor.The overflow valve is configured to move between an open position inwhich water flow is permitted between a tank of the toilet and a bowl ofthe toilet through the overflow valve and a closed position in which theoverflow valve substantially prevents water flow from the tank to thebowl. The overflow valve is moveable between the open position and theclosed position in response to a control signal. The control valve isconfigured to selectively send a control signal to the overflow valve.The water level sensor includes a base and a moveable portion that ismoveable relative to the base. The water level sensor defines a portionof a fluid passage, preferably an air passage, which communicates withthe control valve. The moveable portion moves relative to the base inresponse to an above-normal water level in the bowl to a position suchthat the moveable portion cooperates with the base to substantiallyblock flow through the fluid passage and thereby cause the control valveto send a control signal to the overflow valve.

Still another preferred embodiment is a toilet overflow preventionsystem including an overflow valve configured to substantially preventwater flow from a tank of the toilet to a bowl of the toilet through theoverflow valve when the overflow valve is in a closed position. Theoverflow valve is configured to move to the closed position in responseto a supply of water directed to a fluid chamber of the overflow valve.A control valve is configured to selectively direct a supply of water tothe overflow valve. The control valve includes a fluid inlet, and firstfluid outlet and a valve body. The inlet receives a supply of water froma water supply source of the toilet. The first outlet is configured todirect a portion of the supply of water to the overflow valve. The valvebody is moveable between a first position in which fluid communicationbetween the inlet and the first outlet is substantially prevented and asecond position in which fluid communication between the inlet and thefirst outlet is permitted. A variable volume control chamber isconfigured to act on the valve body, wherein at a first volume of thecontrol chamber, the valve body is in the first position and at a secondvolume of the control chamber, the valve body is moved to the secondposition. A water level sensor is configured to sense an above-normalwater level in the bowl and communicate with the control chamber. Thewater level sensor is configured to change a pressure within the controlchamber to move the control chamber from the first volume to the secondvolume.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentinvention are described below with reference to preferred embodiments,which are intended to illustrate but not to limit the present invention.The drawings include eighteen figures.

FIG. 1 is a side, partial cross-sectional view of a toilet incorporatingan overflow prevention device including certain features, aspects andadvantages of the present invention. The toilet generally includes abase, defining a bowl, and a tank supported on the base. An interior ofthe tank communicates with the bowl through a passage.

FIG. 2 is a schematic illustration of the toilet and the overflowprevention device of FIG. 1. The illustrated overflow prevention devicegenerally includes an overflow valve assembly, a control valve and awater level sensor.

FIG. 3 is a perspective view of the overflow valve assembly and controlvalve of the overflow prevention device of FIG. 1.

FIG. 4 is an exploded view of the overflow valve assembly and controlvalve shown in FIG. 3.

FIG. 5 is a top, plan view of the overflow valve assembly and controlvalve shown in FIG. 3.

FIG. 6 is a partial cross-sectional view of the overflow valve assemblyand control valve shown in FIG. 3, taken along the view line 6-6 of FIG.5.

FIG. 7 is a partial cross-sectional view of a fluid cylinder assembly ofthe control valve shown in FIG. 3, taken along the view line 7-7 of FIG.5.

FIG. 8 is a partial cross-sectional view of the control valve shown inFIG. 3, taken along view line 8-8 of FIG. 5.

FIG. 9 is a schematic illustration of a modification of the overflowprevention device of FIG. 1, wherein the water level sensor comprises afloat. In addition, a transmission mechanism between the fluid cylinderassembly and the overflow valve comprises a rack and pinion arrangement.

FIG. 10 is a side, partial cross-sectional view of a toiletincorporating an overflow prevention system having certain features,aspects and advantages of a preferred embodiment of the presentinvention.

FIG. 11 is a schematic illustration of the toilet and the overflowprevention system of FIG. 10. The illustrated overflow prevention systemgenerally includes an overflow valve assembly, a control valve and awater level sensor.

FIG. 12 is a perspective view of the overflow valve assembly and controlvalve of the overflow prevention system of FIG. 10.

FIG. 13 is the overflow valve assembly and control valve of FIG. 12,with the flapper valve removed.

FIG. 14 is an exploded view of the overflow valve assembly and controlvalve of FIG. 12.

FIG. 15 is a top, plan view of the overflow valve assembly and controlvalve of FIG. 12.

FIG. 16 is a partial cross-sectional view of the overflow valve assemblyand control valve of FIG. 12, taken along the view line 16-16 of FIG.15.

FIG. 17 is a partial cross-sectional view of a fluid cylinder assemblyof the control valve shown in FIG. 12, taken along the view line 17-17of FIG. 15.

FIG. 18 is a partial cross-sectional view of the control valve of FIG.12, taken along view line 18-18 of FIG. 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a preferred embodiment of the toilet overflowprevention device 10 incorporated within a toilet 12. The toilet 12preferably is of a conventional configuration and includes a base 14 anda tank 16 supported on the base 14. Although the overflow preventiondevice 10 is described herein in the context of such a toilet 12 havinga base 14 and a tank 16, the device 10 may be adapted for use withtoilets having alternative configurations, as will be appreciated by oneof skill in the art in view of the present disclosure.

The base 14 defines a bowl 18, which is configured to hold a volume ofwater 20. A siphon tube 22 connects the bowl 18 with a wastewaterplumbing system 24. The siphon tube 22 extends in an upward directionfrom a lower portion of the bowl 18 and then curves into a downwarddirection toward the lower end of the base 14 to meet the wastewaterplumbing system 24. Accordingly, the height of the upper curve 14 adetermines a normal water level W_(N) within the bowl 18.

Preferably, the tank 16 is of a hollow construction and defines aninterior space configured to hold a volume of water 20. The volume ofwater 20 in the tank 16 preferably defines a normal water level W_(T).Thus, the interior of the tank 16 is the divided into a water portionP_(W) and an air portion P_(A). Preferably, an open upper end of thetank 16 is covered by a lid 28.

Water 20 is evacuated from the tank 16 through an outlet 30 defined by alower wall of the tank 16. Water 20 passing through the outlet 30 movesto the bowl 18 through a passage 32 and gallery 34. The passage 32extends generally vertically from the tank outlet 30 to the gallery 34.The gallery 34 is oriented in a horizontal plane and, preferably,substantially surrounds the bowl 18 at its upper edge, or rim. Openings36 permit water 20 to flow from the gallery 34 into the bowl 18.

With additional reference to FIG. 2, the toilet 12 includes a primaryflush valve, or flapper valve 38. The illustrated flapper valve 38pivots between a closed position, wherein water 20 within the tank 16 issubstantially prevented from flowing through the tank outlet 30, to anopen position, wherein the water 20 within the tank 16 is permitted toflow through the tank outlet 30 and into the bowl 18 through the passage32 and the openings 36 of the gallery 34. The flapper valve 38 iscontrolled by a handle 40 external to the tank 16, which permits a userto activate flushing of the toilet 12.

The toilet 12 also includes a tank fill mechanism 42 configured torefill the tank 16 with water 20 from an external water supply source 44after the tank 16 has been emptied, or the volume of water 20 reduced,during a flush cycle. The tank fill mechanism 42 includes a filler valve46, which is typically supported at a height above the lower end of thetank 16 by a support structure 48. The filler valve 46 is configured toselectively permit water 20 from the water supply 44 to fill the tank 16and, typically, the bowl 18.

The filler valve 46 supplies water 20 to the tank 16 and the bowl 18through a supply line 50. Preferably, the supply line 50 includes afirst branch, or tank supply branch 52 and a second branch, or bowlsupply branch 54. The tank supply branch 52 supplies water 20 directlyinto the interior of the tank 16. Optionally, a back-pressure valve maybe provided in the supply line 50 to create a desired pressure upstreamof the back-pressure valve. Thus, the back-pressure valve may beutilized to alter the supply pressure of the water supply source 44.However, it is contemplated that in most applications, the back-pressurevalve will be omitted.

The bowl supply branch 54 supplies water 20 to the bowl 18 through anoverflow tube 56. The overflow tube 56 includes an open upper end 58 anda lower end 60, which defines a discharge opening 62. The bowl supplybranch 54 supplies water 20 to an internal passage of the overflow tube56 through the upper end 58 and water is discharged through thedischarge opening 62.

Preferably, the upper end 58 of the overflow tube 56 is positioned abovea normal water level W_(T) within the tank 16. The discharge opening 62preferably is positioned below the flapper valve 38 to permit water 20within the tank to move into the bowl 18 through the overflow tube 56when the flapper valve 38 is in a closed position. Thus, the overflowtube 56 permits water 20 above a normal water level W_(T) to bypass theflapper valve 38 in the event that the water level within the tank 16rises above the upper end 58 of the overflow tube 56. For example, inthe event of a malfunction of the filler valve 46. The overflow tube 56also permits the filler valve 46 to supply water 20 to the bowl 18through the discharge opening 62 when the flapper valve 38 is in aclosed position.

The filler valve 46, in the illustrated arrangement, is controlled by atank water level sensor in the form of a float 64. Thus, the float 64preferably defines the normal water level W_(T) within the tank 16 bymoving the filler valve 46 to a closed position upon reaching a desiredwater level W_(T).

The illustrated embodiment of the overflow prevention device 10generally includes an overflow valve assembly 70, a control valve 72 anda water level sensor 74. The overflow valve assembly 70 is configured toselectively permit, or prevent, water 20 from flowing from the tank 16to the bowl 18 regardless of the position of the flapper valve 38.Preferably, the overflow valve assembly 70 is positioned between theflapper valve 38 and the bowl 18 and, more preferably, is positionedgenerally within the passage 32 between the tank 16 and the gallery 34.

The control valve 72 preferably functions as an actuator to move theoverflow valve assembly 70 between an open position and a closedposition. In the illustrated arrangement, the control valve 72 isconfigured to receive a control signal from the water level sensor 74and to send a control signal to the overflow valve assembly 70 to movethe overflow valve assembly 70 between an open and closed position.

The water level sensor 74 is configured to sense an above-normal waterlevel within the bowl 18 and send a signal to the control valve 72 inresponse to such a condition. An above-normal water level within thebowl 18 may be defined as any water level above the normal water levelW_(N). Desirably, the above-normal water level is predetermined duringthe design and/or setup of the device 10. Although the water levelsensor 74 is configured to determine an above-normal water level withinthe bowl 18, preferably, the sensor 74 determines a level of waterwithin the gallery 34 or passage 32 presuming such a level is below anupper end of the bowl 18. However, in alternative arrangements, thesensor 74 may determine an above-normal water level from within the bowl18, or an alternative location that has a water level indicative of thewater level within the bowl 18.

The overflow valve assembly 70 preferably includes a base 76, whichpasses through the outlet 30 of the tank 16 and into the passage 32. Theillustrated base 76 includes an upper portion 78 and a lower portion 80.The upper portion 78 resides within the tank 16 and supports the base 76on the flapper valve assembly 38 or, alternatively, on an interiorsurface of the tank 16. The lower portion 80 is a hollow, cylindricalmember, which extends downwardly from the upper portion 78 through theoutlet 30 and into the passage 32.

The overflow valve assembly 70 also includes a cup 82 supported by thebase 76. Preferably, the cup 82 includes an upper flange 84, which restson the base 76, and an annular portion 86, which extends downwardly intothe interior space of the lower portion 80 of the base 76. Preferably,the annular portion 86 of the cup 82 fits relatively snugly within thelower portion 80 of the base 76 while permitting the cup 82 to rotatewith respect to the base 76.

A valve gate, or a stopper 88, is connected to the cup 82 through one ormore couplers 90. The stopper 88 is configured to substantially entirelyclose off the lower end 80 of the base 76 to substantially prevent waterfrom passing through the overflow valve assembly 70. A complete sealbetween the stopper 88 and the base 76 is preferred, however, it is tobe understood that some amount of water may be permitted to move pastthe stopper 88 in its closed position. For example, an incomplete sealbetween the stopper 88 and base 76 may result due to normalmanufacturing variations.

The stopper 88 is “keyed” to the base 76 to prevent rotation of thestopper 88 about an axis A of the passage 32 relative to the base 76.Accordingly, when the cup 82 is rotated relative to the base 76 (and thestopper 88) the effective length of the couplers 90 is shortened to drawthe stopper 88 toward the lower end 80 of the base 76 to the closedposition of the stopper 88. That is, the couplers 90 move from aposition substantially parallel to the axis A to a position wherein anaxis of each coupler 90 forms an angle with the axis A.

In the illustrated arrangement, two couplers 90 are provided in the formof chain members, preferably similar in construction to the chain oftenused to connect the flapper valve 38 to the handle 40. However, othersuitable couplers 90 may also be used that preferably are substantiallyfixed in length and capable of withstanding a load imparted onto thecouplers 90 due to the weight of the water 20 within the tank 16. Inaddition, varying numbers of couplers 90 may be used, including a singlecoupler 90. Other suitable arrangements for converting rotational motionof the cup 82 into linear movement of the stopper 88 may also beemployed.

An actuating arm 92 extends generally outward from the flange 84 of thecup 82 in a radial direction. The arm 92 is coupled to an output of anactuator, or fluid cylinder 94, which is configured to apply a force tothe actuating arm 92 to rotate the cup 82 relative to the base 76. Thefluid cylinder 94 includes a housing, or case 96, that defines aninternal, preferably cylindrical bore 98. However, the bore 98 may be ofother shapes as well. A piston 100 is configured for reciprocationwithin the bore 98. Together, the piston 100 and the case 96 define avariable volume fluid chamber 102. Thus, as used herein, “fluidcylinder” desirably refers to an assembly comprising a piston membermovable relative to a chamber-defining member, or other equivalentstructures, and is not necessarily limited to cylindrical structures.

A piston rod 104 is coupled to the piston 100 and extends from thepiston 100 in a direction opposite the fluid chamber 102. The piston rod104 is coupled to the actuating arm 92 of the cup 82 through a suitableconnector, such as a shaft 106. Preferably, the shaft 106 is configuredto rotate with respect to one or both of the piston rod 104 and theactuating arm 92. Thus, the piston rod 104, shaft 106 and actuating arm92 operate as a transmission mechanism to convert linear motion of thepiston 100 into rotational motion of the cup 82. In addition, othersuitable motion conversion and/or transmission mechanisms may also beused.

The case 96 also includes a port 108 to permit fluid to move into or outof the fluid chamber 102. Preferably, the port 108 is defined by an endof the case 96 opposite the piston rod 104.

As described above, the control valve 72 is configured to receive acontrol signal from the water level sensor 74 and to actuate theoverflow valve assembly 70 in response to the control signal. In theillustrated embodiment, the control valve includes a housing 110, whichdefines a first or upper fluid chamber 112 and a second, or lower fluidchamber 114. Desirably, the upper chamber 112 and lower chamber 114 areseparated from one another. The control valve 72 includes an inlet 116and a pair of outlets 118, 120 that communicate with the upper chamber112.

Preferably, a valve 122 selectively permits fluid communication betweenthe upper chamber 112 and the outlet 120. In the illustrated embodiment,the outlet 120 defines an opening 124 that opens into the upper chamber112 and is surrounded by a valve seat 125 (FIG. 8). A ball member 126 issized and shaped to cooperate with the valve seat 125 of the opening 124to selectively block the opening 124 and substantially prevent fluidflow from the upper chamber 112 through the outlet 120. When the ballmember 126 is removed from the valve seat of the opening 124 fluid flowis permitted from the upper chamber 112 to the outlet 120.

Desirably, a baffle plate 128 is positioned between the inlet 116 andthe ball member 126. Preferably, the baffle plate 128 is a disk-likemember that contacts an outer wall of the upper chamber 112 along itsentire periphery. The baffle plate 128 includes one or more openings130, which permit fluid to flow from the inlet, through the baffle plate128, toward the ball member 126. However, the baffle plate 128 desirablyinhibits the flow of incoming water from disturbing the position of theball member 126 relative to the valve seat 125 of the opening 124.Alternatively, other suitable baffle arrangements may be used, ifnecessary or desired.

The ball member 126 is moved between an open and closed position by avalve actuation mechanism 132. In the illustrated embodiment, the valveactuation mechanism 132 includes a push rod 134 moveable by a diaphragm136. Preferably, the diaphragm 136, in a relaxed position, positions thepush rod 134 such that an upper end of the push rod 134 moves the ballmember 126 off of the valve seat 125 of the opening 124 to an openposition wherein fluid is permitted to flow from the upper chamber 112to the outlet 120.

The diaphragm 136 is responsive to water pressure within the lowerchamber 114 to move to a second position wherein the push rod 134 islowered to permit the ball member 126 to engage the valve seat of theopening 124 and substantially prevent water flow from the upper chamber112 to the outlet 120. The ball member 126 preferably is urged intoengagement with the valve seat 125 by water pressure within the upperchamber 112. However, the ball member 126 may also be biased intoengagement with the valve seat 125 by a suitable biasing arrangement,such as a spring, for example.

In the illustrated arrangement, the control valve 72 receives a supplyof water from the external water supply 44. The supply of water isdelivered into the upper chamber 112 through the inlet 116 by a firstbranch 50 a of the supply line 50. Preferably, water received from theinlet 116 is permitted to pass substantially uninterrupted from theupper chamber 112 through the outlet 118 to the tank supply branch 52and bowl supply branch 54, as described above.

In addition, water within the upper chamber 112 is permitted to flowthrough the outlet 120 when the valve 122 is in an open position (e.g.,the ball member 125 is disengaged from the valve seat 125). Waterexiting the outlet 120 flows through a supply line 140 to the fluidchamber 102 of the fluid cylinder 94 to actuate the piston 100,preferably as described above.

The lower chamber 114 includes an inlet 142, which permits water to flowfrom a control line 144 into the lower chamber 114. Desirably, waterflow within the control line 144 is selectively provided by the waterlevel sensor 74. Thus, in the illustrated embodiment, the control signalfrom the water level sensor 74 comprises the presence or absence of aflow of water through the control line 144 and into the lower chamber114 to influence a position of the diaphragm 136, as described above.

The water level sensor 74 is configured to detect an above-normal waterlevel within the bowl 18 of the toilet 12 and, in response, send acontrol signal to the control valve 72. In the illustrated embodiment,the water level sensor 74 includes a main water line 150 defining apassage 150 a, a first branch line 152 defining a passage 152 a and asecond branch line 154 defining a passage 154 a. The passages 150 a, 152a, 154 a communicate with one another.

The main line 150 includes a first end, or inlet end 156 and a secondend, or discharge end 158. The main line 150 receives a supply of waterfrom the external water supply 44 through the inlet 156 from a secondbranch 50 b of the supply line 50.

The first branch line 152 is coupled to the main line 150 at a first end160. The first branch line 152 also includes a second end 162 definingan opening 164 communicating with the first branch passage 152 a. Theopening 164 operates as a water level sensing mechanism, as is describedin greater detail below.

The second branch line 154 includes a first end 166 coupled to the mainline 150, preferably at a position upstream from the first branch line152. The second branch line 154 also includes a second end 168, whichdefines an opening 170 communicating with the second branch passage 154a. The second branch line 154 also includes an outlet 172, whichsupplies a flow of water to the control line 144 coupled to the inlet142 of the lower chamber 114 of the control valve 72.

A valve 174 is positioned within the second branch line 154 between thefirst end 166 and the second end 168. The valve 174 has a first positionwherein water is permitted to flow from the first end 166 through theoutlet 172. Preferably, in the first position of the valve 174, water issubstantially prevented from flowing through the second end 168 of thesecond branch passage 154 a. In a second position of the valve 174,water is substantially prevented from flowing from the first end 166 ofthe second branch passage 154 a through the outlet 172 and into thecontrol line 144.

In the illustrated arrangement, the valve 174 includes a housing 176defining an interior chamber 178. The first end 166 of the second branchpassage 154 a communicates with the chamber 178 through a first opening180. Similarly, the second end 168 of the second branch passage 154 acommunicates with the chamber 178 through a second opening 182. A firstvalve seat 184 surrounds the first opening 180 and is preferablyhemispherical in shape with a concave surface facing the chamber 178. Asecond valve seat 186 surrounds the second opening 182 and is alsohemispherical in shape and also with a concave surface facing thechamber 178.

A ball member 188 is positioned within the chamber 178 and is moveablebetween a position engaged with the first valve seat 184 and a positionengaged with the second valve seat 186 to selectively prevent fluid flowthrough the first opening 180 and the second opening 182, respectively.When the ball member 188 is engaged with the second valve seat 186 fluidflows permitted from the first end 166 of the second branch passage 154a through the chamber 178 and out the outlet 172 to the control line144. Conversely, when the ball member 188 is engaged with the firstvalve seat 184 fluid flow from the first end 166 of the second branchpassage 154 a is not permitted into the chamber 178 and, thus, no fluidflow is permitted through the control line 144. Although, theabove-described valve assembly is preferred, other suitable valvearrangements may also be used within the water level sensor 74. Indeed,other suitable water level sensors may be alternatively used inconnection with the device 10.

Desirably, the outlets 159, 170 of the main line 150 and the secondbranch line 154, respectively, are positioned within an air space.Preferably, the outlets 159, 170 are positioned within the airspaceP_(A) of the tank 16. Desirably, the first branch line 152 extends fromthe main line 150 through the water 20 within the tank 16 and throughthe overflow valve assembly 70 into the gallery 34 of the base 14.However, the second end 162 may also be positioned within the bowl 18,as will be appreciated by one of skill in the art. Desirably, theopening 164 of the second end 162 of the first branch line 152 ispositioned above a normal water level W_(N) within the bowl 18. Theopening 164 preferably is positioned at a desired above-normal waterlevel.

When the filler valve 46 is in a position permitting water to flow fromthe water supply 44 to the supply line 50, the main passage 150 areceives a flow of water from the supply line branch 50 b at its inletend 156. Water flows from the inlet end 156 through the main passage 150a and exits from the discharge end 158. Upon passing the junctionbetween the main passage 150 a and the first branch passage 152 a, thewater flow within the main passage 150 a mixes with air drawn into thewater stream from the first branch passage 152 a when the opening 164 isnot immersed in water 20 (e.g., the water 20 in the bowl 18 is below theabove-normal water level).

Thus, downstream from the junction between the main passage 150 a and afirst branch passage 152 a, a mixture of water and air flows through themain passage 150 a when the opening 164 is not immersed in water 20. Themixture of both water 20 and air downstream of the first branch passage152 a subjects the water 20, alone, upstream of the first branch passage152 a to a relative high-pressure condition. As a result, water flowsinto the first end 166 of the second branch passage 154 a and moves theball member 188 away from the first valve seat 184 and, preferably, intoengagement with the second valve seat 186. Water is then permitted toflow through the outlet 172 and into the control line 144, therebybiasing the control valve 72 into a closed position wherein water 20 isnot permitted to flow through the outlet 120 and to the fluid cylinder94.

If the water 20 within the bowl 18 (or gallery 34) rises to a sufficientlevel to cover the opening 164 of the first branch line 152 (i.e., anabove-normal water level), no air is drawn into the first branch passage152 a in response to water flow past the first branch passage 152 a. Asa result, air is drawn through the opening 170 of the second branchpassage 154 a, in response to water 20 within the main passage 150 aflowing past the second branch passage 154 a and moves the ball member188 away from the second valve seat 186. Preferably, the ball member 188is moved into engagement with the first valve seat 184 therebysubstantially preventing water from flowing from the first end 166 ofthe second branch line 154 through the chamber 178 and outlet 172 andinto the control line 144. Accordingly, no water 20 is provided to thelower chamber 114 and the control valve 72 moves to an open positionwherein water is supplied to the fluid cylinder 94.

In operation, the overflow prevention device 10 utilizes the water levelsensor 74 to indirectly detect an above-normal water level within thebowl 18 and, in response, send a control signal to the control valve 72.The control valve 72 in response to the control signal actuates theoverflow valve assembly to move the stopper 88 to a closed positionthereby preventing water 20 within the tank 16 from moving from the tank16 to the bowl 18. Accordingly, overflowing of the toilet bowl 18 isprevented.

Specifically, when a user actuates the handle 40 to flush the toilet 12,the flapper valve 38 is opened to permit water 20 within the tank 16 toflow past the flapper valve 38. If an above-normal water level does notexist as determined by the water level sensor 74, a flow of water isdelivered to the lower chamber 114 of the control valve 72. As a result,the control valve 72 does not actuate the overflow valve assembly 70 andthe stopper 88 remains in an open position. Accordingly, water 20 withinthe tank 16 is permitted to flow past the flapper valve 38 and throughthe overflow valve assembly 70 to the bowl 18 passing through thepassage 32 and the gallery 34.

In response to the water 20 vacating the tank 16, the float 64 moves toa lowered position to open the filler valve 46 and permit a flow ofwater to flow from the water supply 44 into the supply line 50. Thewater within the supply line 50 branches into the first branch 50 amoves through the upper chamber 112 of the control valve 72 and throughthe bowl supply branch 54 and tank supply branch 52 to fill the bowl 18and the tank 16, respectively. Water flowing through the second branch50 b of the supply line 50 flows through the main passage 150 a of thewater level sensor 74 and discharges from the discharge end 158, alongwith air drawn from the first branch passage 152 a. Preferably, asdescribed above, the discharge end 158 of the main line 150 ispositioned within the air space P_(A) of the tank 16 and the dischargedwater from the main line 150 also fills the tank 16. Once the waterlevel within the tank 16 has reached a normal level W_(T), the float 64operates to shut off the filler valve 46, which prevents a flow of waterfrom the water supply 44 into the supply line 50.

In contrast, in the event of an above-normal water level reading by thewater level sensor 74 when the toilet is flushed, no water is sent tothe control valve 72 from the water level sensor 74 and, therefore, acontrol valve 72 actuates the flow valve assembly 70 to close thestopper 88. Therefore, water flow from the tank 16 to the bowl 18 isprevented. Desirably, the stopper 88 remains in a closed position atleast until the tank 16 is filled to the normal tank level W_(T),whereupon the float 64 shuts off the filler valve 42. Once theabove-normal water level condition is removed, water pressure from waterwithin the tank 16 acting on the stopper 88 may move the stopper 88 toan open position when the flapper valve 38 is opened to once againpermit water to move from the tank 16 to the bowl 18 in a normal manner.Movement of the stopper 88 also moves the piston 100 to its relaxedposition. Alternatively, the piston 100 may be biased to its relaxedposition to move the stopper 88 to an open position in the absence of anabove-normal water level by a suitable biasing arrangement, such as aspring, for example.

FIGS. 3-8 illustrates a specific construction of a presently preferredoverflow valve assembly 70 and control valve 72, which operate asdescribed above with reference to FIGS. 1 and 2. Preferably, the base 76includes an upper portion 78 and a lower portion 80, as noted above.With reference to FIG. 3, preferably, the upper portion 78 includes aplanar, upper wall 200 and a side wall 202 that extends downwardly froma periphery of the upper wall 200 on at least three sides of the upperwall 200. The lower portion 80 comprises a hollow, cylindrical member204 that is unitary with the upper wall 200. Alternatively, thecylindrical 204 may be a separate piece connected to the upper wall 200.The hollow, inner bore of the cylindrical member 204 defines apassageway 206.

With reference to FIG. 4, the upper wall 200 includes a circular opening208 which permits communication with the passageway 206 of thecylindrical member 204. A side channel 210 extends toward the opening208 in a radial direction. An inlet port 212 is defined within the sidewall 202 to permit fluid communication with the side channel 210. Asecondary passageway 214 (FIG. 6) extends alongside the passageway 206and communicates with the side channel 210 at is upper end. The sidechannel 210 and secondary passageway 214 permit a flow of water throughthe overflow tube 56 and discharge opening 62 to bypass the overflowvalve assembly 70 and refill the bowl 18 when the overflow valveassembly 70 is in the open position. Alternatively, other suitablearrangements may be used to permit water to bypass the overflow valveassembly 70 to fill the bowl 18 when the overflow valve assembly 70 isin the open position.

Preferably, a cover 216 is connected to the upper wall 200 by a pair oftabs 218 (only one shown) received within slots 220 defined by the upperwall 200. The cover 216 includes an annular portion 222 and a projectingportion 224. The annular portion 222 is sized to surround the opening208 of the upper portion 78 of the base 76. The projecting portion 224extends generally radially away from the annular portion 222 and issized and shaped to cover the side channel 210 of the upper portion 78.

Preferably, an upper surface of the annular portion 222 of the cover 216defines a raised bearing surface 226. Preferably, the bearing surface226 is annular in shape and also surrounds the opening 208. The bearingsurface 226 preferably is semi-circular in section to define a lowfriction surface for the cup 82 to rotate upon. Although an annularbearing surface 226 is shown, alternative arrangements are possiblewhere the bearing surface 226 does not completely encircle the opening208. For example, the bearing surface 226 may be interrupted along theperiphery of the opening 208 or may comprise one or more distinct,raised surfaces configured to support the cup 82.

To “key” the stopper 88 with respect to the base 76, an internal surfaceof the cylindrical member 204 defines an opposed pair of semi-circularprojections 230, which extend inwardly into the passageway 206.Preferably, a ring 232 is shaped similarly to a lower-end surface of thecylindrical member 204 and is coupled thereto. The projections 230cooperate with elongated, semi-cylindrical guides 234, which extend inan upward direction from an upper surface of the stopper 88. Asdescribed above, the guides 234 and projections 230 prevent the stopper88 from rotating relative to the cylindrical member 204 of the base 76when the cup 82 rotates. Thus, rotation of the cup 82 results in linearmovement of the stopper 88 through one or more couplers therebetween,such as the chain 90.

Desirably, a seal 236 is positioned between the stopper 88 and a lowersurface of the ring 232 to provide a seal therebetween when the stopper88 is in a closed position. A pair of tabs 238 are provided to permitthe chain 90 to be connected between the stopper 88 and the cup 82.

Preferably, the cup 82 is a hollow, cylindrical member as describedabove, including the flange 84 and the base 86. An extension 240projects radially from the flange 84 and is configured for connection tothe actuating arm 92 of the fluid cylinder 94. In addition, preferably,the base 86 of the cup 82 includes a plurality of openings, or slots 241extending around a periphery of the base 86.

As described above, preferably, the fluid cylinder arrangement 94includes a piston 100 connected to a piston rod 104. The actuating arm92 is connected to the piston rod 104 to translate linear motion of thepiston rod 104 into rotational motion of the cup 82. With reference toFIG. 4, preferably the actuating arm 92 includes a first arm portion 242and a second arm portion 244 that define an angle therebetween.Preferably, the angle is approximately 120°.

In the illustrated arrangement, the case 96 of the fluid cylinderarrangement 94 is generally rectangular in cross-sectional shape anddefines the cylindrical fluid chamber 102. Preferably, a piston rodsupport 246 is coupled to an end of the case 96 to support an end of thepiston rod 104 opposite the piston 100 and includes a bushing 247 (FIG.7) to facilitate sliding movement of the piston rod 104.

With reference to FIG. 8, a preferred control valve 72 is illustrated.As described above, the control valve 72 includes an upper chamber 112and a lower chamber 114. A diaphragm 136 is positioned within the lowerchamber 114 and is responsive to water pressure therein to move betweena biased position and a relaxed position. In the illustrated embodimentof FIGS. 3-5, the diaphragm 136 is substantially planar in its relaxedposition. The push rod 134 is sized such that the ball member 126 ismoved away from the valve seat 125 of the opening 124 when the diaphragm136 is in its relaxed position.

Desirably, the diaphragm 136 separates the lower chamber 114 from anambient chamber 250. The ambient chamber 250 includes a vent 252 thatpermits water 20 within the tank 16 to enter the ambient chamber 250.The water within the ambient chamber 250, when no water is supplied tothe lower chamber 114, assists the diaphragm 136 in moving to itsrelaxed position. When water is supplied to the lower chamber 114, acentral portion of the diaphragm 136 is flexed downwardly to displacewater from the ambient chamber 250 and lower the push rod 134 to permitthe ball member 126 to seat on the valve seat 125 of the opening 124.

Although such an arrangement is preferred, alternative arrangements arepossible. For example, the ambient chamber 250 may be omitted and thediaphragm 136 may be configured to be normally convex such that itscentral portion bows upwardly to move the push rod 134 in an upwarddirection to displace the ball member 126 from the valve seat 125 of theopening 124 in a relaxed position of the diaphragm 136, as shown in thearrangement of FIG. 2. Other arrangements are also possible, as will beappreciated by one of skill in the art.

FIG. 9 is a schematic illustration of a modification of the overflowprevention device 10 of FIGS. 1-8 and is referred to generally by thereference numeral 10′. The device 10′ is substantially similar to thedevice 10 and, therefore, like reference numerals will be used to denotelike components, except that a prime (′) has been added. Preferably, thedevice 10′ of FIG. 9 is substantially similar to the device 10 of FIGS.1-8 with the exception of the overflow valve assembly 70′ and thecontrol valve 72′.

In the overflow valve assembly 70′ of FIG. 9, the piston 100′ is coupledfor linear movement with a rack 300, which includes a plurality of gearteeth 302. An outer peripheral edge of the cup 82′ defines a pinion gear304 including a plurality of gear teeth 306. The gear teeth 306 of thepinion gear 304 are configured to engage the gear teeth 302 of the rack300. Thus, linear motion of the piston 100′ is converted to rotationalmotion of the cup 82′ the rack 300 and pinion 304 mechanism, whichfunctions as a transmission mechanism.

Furthermore, the water level sensor 74′ of FIG. 9 comprises a float 310,preferably positioned within the passage 32′ between the tank 16′ andthe bowl 18′. The push rod 134′ is coupled to the float 310 such thatwhen the float is raised by an above-normal water level the ball member126′ is displaced from the valve seat of the opening 124′ and the piston100′ is actuated. Preferably, in all other respects, the device 10′ ofFIG. 9 operates in a substantially similar manner to the device 10 ofFIGS. 1-8.

FIGS. 10-18 illustrate a modification of the toilet overflow preventiondevice, system 10, of FIGS. 1-8 incorporated within a toilet 12″. Thetoilet overflow prevention system of FIGS. 10-18 is similar to thetoilet overflow prevention device 10 of FIGS. 1-8 and, therefore, likereference numerals are used to denote like components, except that adouble prime (″) is added. Components of the system 10″ not described indetail hereafter may be assumed to be the same or similar to thecorresponding components described above in relation to the device ofFIGS. 1-8 or the device of FIG. 9.

The overflow prevention device, system 10″, is configured to detect anabove-normal water level within the bowl 18″ of the toilet 12″ andsubstantially inhibit or prevent a flow of water from the tank 16″ tothe bowl 18″ in response to the above-normal water level condition. Withreference to FIG. 11, the overflow prevention system 10″ generallyincludes an overflow valve assembly 70″, a control valve 72″ and a waterlevel sensor 74″. The overflow valve assembly 70″ is configured toselectively permit water 20″ to flow from the tank 16″ to the bowl 18″through the control valve 72″ regardless of the position of the flappervalve 38″. The control valve 72″ preferably functions as an actuator tomove the overflow valve assembly 70″ between the open position and theclosed position. The control valve 72″ is configured to receive acontrol signal from the water level sensor 74″ and to send a controlsignal to the overflow valve assembly 70″ to move the overflow valveassembly 70″ between the open and closed position. The water levelsensor 74″ is configured to sense an above-normal water level within thebowl 18″ and, in response, send a signal to the control valve 72″.

The overflow valve assembly 70″ preferably is substantially similar tothe overflow valve 70 of FIGS. 1-8. The overflow valve assembly 70″includes a cup 82″ supported on a base 76″. The cup 82″ is rotatablerelative to the base 76″ to move a stopper 88″ between an open and aclosed position to selectively permit or inhibit water flow between thetank 16″ and the bowl 18″ of the toilet 12″, respectively. A fluidcylinder 94″ is configured to selectively rotate the cup 82″. The system10″ is configured to selectively direct a supply of water from the watersource 44″ of the toilet 12″ to the fluid cylinder 94″. In response toreceiving a supply of water, a piston 100″ and piston rod 104″ of thefluid cylinder 94″ are configured for linear movement. An actuating arm92″ transforms the linear movement of the piston rod 104″ intorotational movement of the cup 82″, substantially as described above inconnection with the fluid cylinder 94 of FIGS. 1-8.

The overflow prevention system 10″ preferably includes a fluid passage400, also referred to herein as a vacuum passage. Desirably, theoverflow valve 70″ defines a portion of the vacuum passage 400. A firstend 400 a of the vacuum passage 400 preferably is vented to theatmosphere and, more preferably, within the air portion P_(A) of thetank 16″. A second end 400 b of the vacuum passage 400 preferablycommunicates with the supply line 50″ and, in the illustratedarrangement, with the bowl supply branch 54″ of the supply line 50″ at aconnection 402.

Between the first end 400 a and the second end 400 b, the vacuum passage400 enters a first port 404 of the overflow valve 70″ and travels froman upper portion 78″ to a lower portion 80″ of the base 76″ through apassage portion 406. The vacuum passage 400 continues through the waterlevel sensor 74″ and then extends from the lower portion 80″ to theupper portion 78″ of the base 76″ through a passage portion 408 and outa second port 410 of the overflow valve assembly 70″. Preferably, theportions 406, 408 of the vacuum passage 400 are defined by the base 76″of the overflow valve assembly. However, in an alternative arrangementthe portions 406, 408 may be defined wholly or partially by members thatare separate from the overflow valve assembly 70″.

The control valve 72″ preferably is substantially similar to the controlvalve 72 of FIGS. 1-8. Desirably, the control valve 72″ includes anupper chamber 112″ and a separate lower chamber, or control chamber114″. An inlet 116″ and a pair of outlets 118″, 120″ communicate withthe upper chamber 112″. A valve 122″ selectively permits fluidcommunication between the upper chamber 112″ and the outlet 120″.Similar to the embodiment described above, the valve 122″ preferablyincludes a valve body, or ball member 126″, which selectively permits orsubstantially prevents fluid flow from the chamber 112″ to the outlet120″.

The fluid chamber 112″ also includes a baffle 128″. In the illustratedarrangement, the baffle 128″ is in the form of a stem extendingdownwardly from an upper wall of the housing 110″ of the valve 72″. Thebaffle 128″ is configured to inhibit fluid flow within the chamber 112″from influencing a position of the ball member 126″.

The inlet 116″ communicates with the supply line 50″ to receive a supplyof water from the water supply source 44″. The outlet 118″ communicateswith the bowl supply passage 54″ to supply the bowl 18″ with water fromthe water supply source 44″ of the toilet 12″. The outlet 120″communicates with a supply line 140″ which delivers water from theoutlet 120″ to the fluid cylinder 94″ to actuate the piston 100″,preferably as described above.

Similar to the embodiments of FIGS. 1-8 and FIG. 9, the control valve72″ includes a valve actuation mechanism 132″. Preferably, the valveactuation mechanism 132″ includes a push rod 134″ that is movable by adiaphragm 136″. Thus, the chamber 114″ is a variable volume chamber thatis responsive to pressure changes within the chamber 114″. The diaphragm136″ moves from a first position at a first pressure within the chamber114″ to a second position at a second pressure within the chamber 114″.Preferably, a biasing member such as 412 (FIG. 18) biases the diaphragm136″ toward the first position wherein the push rod 134″ is positionedsuch that the ball member 126″ inhibits fluid from passing from thechamber 112″ to the outlet 120″. When the pressure within the chamber114″ is reduced to a sufficient level, the biasing force of the spring412 is overcome and the diaphragm 136″ moves such that the volume of thechamber 114″ is reduced. As a result, the diaphragm 136″ moves the pushrod 134″ to a position to move the ball member 126″ away from its valveseat and permit fluid flow from the chamber 112″ to the outlet 120″.

Preferably, a port 142″ permits communication between the lower chamber114″ and a control line 144″. The control line 144″ is connected to thevacuum passage 400. Thus, changes in pressure within the vacuum line 400preferably results in a similar change in pressure within the chamber114″.

As described above, the water level sensor 74″ is configured to sense anabove-normal water level within the bowl 18″ of the toilet 12″. Thewater level sensor 74″ of FIGS. 10-18 preferably is configured to bepositioned within a bowl 18″ of the toilet 12″ and, in the illustratedarrangement, within the gallery 34″. Preferably, the water level sensor74″ is positioned below and, desirably, attached to the overflow valveassembly 70″. The water level sensor 74″ may also be referred to as a“foot valve” herein due to its position below the overflow valve 70″.

The illustrated water level sensor 74″ includes a base 420 and a movableportion, or float 422. The movable portion or float 422 preferably hasan average density that is less than the density of water, making themovable portion 422 buoyant in water. The movable portion 422 is movablerelative to the base 420. In the illustrated arrangement, the movableportion 422 is pivotably coupled to the base 420.

The base 420 preferably defines a portion 424 of the vacuum passage 400between the portion 406 and the portion 408 of the overflow valveassembly 70″. The movable portion 422 includes a post 426 that extendsupwardly from the movable portion 422. A diaphragm 428 is interposedbetween the post 426 and the base 420. Preferably, the diaphragm 428 issecured to the base 420. The movable portion 422 is movable between afirst position, or lowered position, to a second, or upward position,wherein the post 426 moves the diaphragm 428 into a position to blockthe portion 424 of the vacuum passage 400. Accordingly, when the movableportion 422 is in its upward, or closed position, airflow through thevacuum passage 400 is substantially inhibited or prevented.

Preferably, the movable portion 422 is normally in its lower positiondue to the force of gravity acting to rotate the movable portion 422downward about its axis of rotation. However, a biasing arrangement maybe provided to normally bias the movable portion 422 into its lowerposition, wherein airflow through the vacuum passage 400 is permitted.Preferably, the movable portion 422 is configured to be buoyant inwater, as described above, such that the movable portion 422 moves intoits upward position in response to a water level generally equal to aheight of the water level sensor 74″ or, more specifically, a height ofthe movable portion 422 in its upward position. However, in anotherarrangement, a separate buoyant member may be provided which actsdirectly or indirectly on the movable portion 422. Furthermore, otherconstructions configured to selectively block air flow through thevacuum passage 400 may also be used.

Desirably, the movable portion 422 preferably includes a lip 430 thatextends beyond an outer diameter of the lower portion 80″ of theoverflow valve assembly 70″. Thus, water passing from the tank 16″ tothe bowl 18″ contacts the lip 430 to bias the movable portion 422 towardits lowered position. Advantageously, such an arrangement inhibitsundesired upward movement of the movable portion 422 due to transientwater beneath and around the movable portion 422 within the gallery 34″.Accordingly, undesirable activation of the overflow valve 70″ when noabove-normal water level condition is present is avoided.

Preferably, the toilet overflow prevention system 10″ include arestrictive orifice 440 within the vacuum passage 400. In theillustrated arrangement, the restrictive orifice 440 is positionedbetween the connection 402 between the second and 400 b of the vacuumpassage 400 and the bowl supply branch 54″ and the connection betweenthe control passage 144″ and the vacuum passage 400. However,alternative placements of the restrictive orifice 440 may also be used.Desirably, the restrictive orifice 440 is configured to limit or controla flow rate of air through the vacuum passage 400. Thus, when air isbeing drawn through the vacuum passage 400, the restrictive orifice 400controls a flow rate to control a pressure within the chamber 114″ ofthe control valve 72″. If desired, the restrictive orifice 440 may beconfigured to be adjustable.

In operation, the system 10″ preferably performs substantially similarto the system 10 of FIGS. 1-8 and the system 10″ of the FIG. 9. During anormal flush cycle, when the water level within the bowl 18″ does notrise above a normal level, water from the water supply source 44″ passesthrough the chamber 112″ of the control valve 72″ and into the bowl 18″through the bowl supply branch 54″ and, preferably, also to the tank 16″through a tank supply branch (not shown). Movement of the water past theconnection 402 between the bowl supply branch 54″ and the second end 400b of the vacuum passage 400 draws air from the atmosphere (air portionP_(A) of the tank 16″) through the first end 400 a of the vacuum passage400. The flow of air through the vacuum passage 400 is permitted becausethe movable portion 422 of the water level sensor 74″ is in its loweredposition. The restrictive orifice 440 limits a flow rate of air throughthe vacuum passage 400. As a result, the pressure within the controlchamber 114″ of the control valve 72″ is not reduced to a sufficientlevel to overcome the biasing force of the spring 412. Thus, thediaphragm 136″ remains in its lowered position and the ball member 126″inhibits fluid from moving from the upper chamber 112″ to the outlet120″ and to the fluid cylinder 94″. Accordingly, the overflow valveassembly 70″ remains in an open position and water flow from the tank16″ to the blow 18″ is permitted.

If the water level within the bowl 18″ rises to a sufficient level tomove the float 422 or movable portion of the water level sensor 74″ toits upward position, the flow of air through the vacuum passage 400 issubstantially reduced or prevented. As a result, the pressure within thecontrol chamber 114″ is reduced to a sufficient level to overcome thebiasing force of the spring 412 due to the venturi effect of the waterwithin the bowl supply line 54″ passing the second end of the 400 b ofthe vacuum passage 400. Thus, the push rod 134″ moves the ball member126″ to a position such that fluid communication is permitted betweenthe chamber 112″ and the outlet 120″ of the control valve 72″. A supplyof water is thus provided to the fluid cylinder 94″ to activate thefluid cylinder 94″ and move the overflow valve assembly 70″ to itsclosed position, as described above. Thus, water flow from the tank 16″to the bowl 18″ is substantially inhibited or prevented. Accordingly,overflow of the toilet bowl 18 ″ is prevented.

Preferably, the fluid cylinder 94″ includes a biasing element, such asspring 442, to bias the piston 100″ to its normal position once a supplyof water is no longer directed to the fluid cylinder 94″ by the controlvalve 72″, thereby resetting the system 10″ for further use. Movement ofthe piston 100″ back toward its normal position may force water backthrough passage 140″ and through the valve 122″. Desirably, the pressureexerted on the water within the fluid cylinder 94″ due to the force ofthe spring 442 provides a sufficient force to move the ball member 126″from its valve seat and permit a substantial portion of the water toexit the fluid cylinder 94″. The water may then move from the upperchamber 112″ of the control valve 72″ to the bowl 18″ through the bowlsupply line 54″.

In an alternative arrangement of the system 10″, the water level sensor74″ is configured to be normally closed. That is, the water level sensor74″ is configured to substantially or completely block the vacuumpassage 400 in the absence of a force tending to move the water levelsensor 74″ to an open position, wherein the vacuum passage 400 is notblocked. Preferably, in such an arrangement, the movable portion 422 ofthe water level sensor 74″ is biased upwardly toward the base 420 by abiasing member, such as a spring, for example. The movable portion 422is configured such that water moving from the tank 16″ to the bowl 18″through the overflow valve 70″ biases the movable portion 422 to an openposition during a normal flush cycle, that is, when the water levelwithin the bowl 18″ is not above a normal-water level W_(N). Preferably,the overflow valve 70″ and/or water level sensor (foot valve) 74″include surfaces or features shaped to direct a flow of water in amanner to facilitate the flow of water producing a force on the movableportion 422 sufficient to bias the moveable portion 422 to the openposition. In such a situation, a significant vacuum within the controlchamber 114″ is not produced and the overflow valve 70″ remains open. Aswill be appreciated by one of skill in the art, during a normal flushcycle, water from the water supply line 50″may potentially be directedto the fluid cylinder 94″ (thus tending to actuate the overflow valve70″) until water from the tank 16″ reaches the water level sensor 74″ tobias the movable portion 422 to the open position. Preferably, thetiming of water reaching the fluid cylinder 94″ is correlated with thetiming for the water level sensor 74″ to be biased to the open positionto reduce or eliminate any undesirable actuation of the overflow valve70″ during a normal flush cycle. Such timing correlation may beaccomplished by any suitable manner, such as by suitably configuring thelength or diameter of any of the systems' 10″ fluid passages and/orsuitably configuring the size, shape or relative position of theoverflow valve 70″, control valve 72″ or water level sensor 74″.

If the water level is above a normal level W_(N) when a flush cycle iscommenced, the water level sensor 74″ will be surrounded by water, orwill soon be surrounded by water if it is not already, due to a risingwater level resulting from the obstruction preventing the bowl 18″ fromemptying at a normal rate. Preferably, in such a situation, the waterlevel sensor 74″ is configured such that water moving from the tank 16″to the bowl 18″ through the overflow valve 70″ does not bias the movableportion 422 to an open position. Preferably, this is because the watermoving from the tank 16″ to the bowl 18″ through the overflow valve 70″flows into a space filled with water, rather than into an air space asoccurs during a normal flush cycle (with a normal water level). As aresult, the water entering from the tank 16″ does not apply a sufficientforce to the moveable portion 422 to bias it into an open position dueto the presence of the water surrounding the water level sensor 74″.Accordingly, the water level sensor 74″ remains in a closed position anda vacuum is created in the vacuum passage 400 due to the venture effectof water in the bowl supply passage 54″ passing the second end 400 b ofthe vacuum passage 400 and, as described above, the pressure changeswithin the control chamber 114″ of the control valve 72″ to actuate thefluid cylinder 94″ of the overflow valve 70″. Thus, the overflow valve70″ is moved to a closed position, preferably as described above, tosubstantially inhibit or prevent additional water from moving from thetank 16″ to the bowl 18″.

Although this invention has been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present invention extends beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the invention and obvious modifications and equivalencethereof. For example, in some standard flapper valve assemblies, theflapper is arranged in a non-horizontal, or slanted, orientation. Thepresent toilet overflow prevention device may include a wedge-likeinsert below the flapper to convert such a non-horizontal flapper valveassembly into essentially a horizontal flapper valve assembly.Optionally, the overflow valve assembly of the present device may bemodified for use with such non-horizontal flapper valve assemblies, orother types of flapper valve assemblies, as will be appreciated by oneof skill in the art.

Furthermore, while the present toilet overflow prevention device hasbeen described in the context of particularly embodiments, the skilledartisan will appreciate, in view of the present disclosure, that certainadvantages, features and aspects of the device may be realized in avariety of other applications, many of which have been noted above.Additionally, it is contemplated that various aspects and features ofthe invention described can be practiced separately, combined together,or substituted for one another, and that a variety of combination andsub-combinations of the features and aspects can be made and still fallwithin the scope of the invention. Thus, it is intended that the scopeof the present invention herein disclosed should not be limited by theparticular disclosed embodiments described above, but should bedetermined only by fair reading of the claims.

1. A toilet overflow prevention system, comprising: an overflow valveconfigured to move between an open position in which water flow ispermitted between a tank of the toilet and a bowl of the toilet throughsaid overflow valve and a closed position in which said overflow valvesubstantially prevents water flow from the tank to the bowl, saidoverflow valve movable between said open position and said closedposition in response to a control signal; a control valve configured toselectively send a control signal to said overflow valve; a water levelsensor comprising a base and a movable portion that is movable relativeto said base, said water level sensor defining a portion of a fluidpassage that communicates with said control valve, wherein said movableportion moves relative to said base in response to an above-normal waterlevel in the bowl to a position such that said movable portioncooperates with said base to substantially block flow through said fluidpassage and thereby cause said control valve to send a control signal tosaid overflow valve, wherein said movable portion comprises a lipconfigured to interfere with water flow from the tank to the bowl,wherein said water flow applies a force to said lip tending to move saidmovable portion away from said base.
 2. The toilet overflow preventionsystem of claim 1, wherein said movable portion is configured to bebuoyant in water.
 3. The toilet overflow prevention system of claim 1,wherein said movable portion is pivotally secured to said base.
 4. Thetoilet overflow prevention system of claim 1, wherein said movableportion comprises a valve body configured to substantially block flowthrough said fluid passage in response to an above-normal water level insaid bowl.
 5. The toilet overflow prevention system of claim 4,additionally comprising a diaphragm positioned between said base andsaid valve body of said movable portion.
 6. The toilet overflowprevention system of claim 1, additionally comprising a restrictionorifice within said fluid passage sized to limit a flow of fluid throughsaid fluid passage.
 7. The toilet overflow prevention system of claim 1,wherein said overflow valve defines a portion of said fluid passage. 8.A toilet overflow prevention system for use with a toilet having a watersupply source, comprising: an overflow valve configured to move betweenan open position in which water flow is permitted between a tank of thetoilet and a bowl of the toilet through said overflow valve and a closedposition in which said overflow valve substantially prevents water flowfrom the tank to the bowl, said overflow valve movable between said openposition and said closed position in response to a control signal; acontrol valve configured to selectively send a control signal to saidoverflow valve; a water level sensor comprising a base and a movableportion that is movable relative to said base, said water level sensordefining a portion of a fluid passage that communicates with saidcontrol valve, wherein said movable portion moves relative to said basein response to an above-normal water level in the bowl to a positionsuch that said movable portion cooperates with said base tosubstantially block flow through said fluid passage and thereby causesaid control valve to send a control signal to said overflow valve,wherein said fluid passage includes a first end and a second end, saidfirst end vented to the atmosphere and said second end communicatingwith a water supply passage connected to said water supply source suchthat water flowing through said water supply passage past said secondend tends to draw atmospheric air through said fluid passage.
 9. Thetoilet overflow prevention system of claim 8, wherein said control valvecomprises a variable-volume control chamber in communication with saidfluid passage.
 10. A toilet overflow prevention system for use with atoilet, comprising: an overflow valve configured to substantiallyprevent water flow from a tank of the toilet to a bowl of the toiletthrough said overflow valve when said overflow valve is in a closedposition, said overflow valve comprising a fluid chamber and beingconfigured to move to said closed position in response to a supply ofwater directed to said fluid chamber; a control valve configured toselectively direct a supply of water to said overflow valve, saidcontrol valve having a fluid inlet, a first fluid outlet and a valvebody, said inlet receiving a supply of water from a water supply sourceof the toilet, said outlet configured to direct a portion of said supplyof water to said overflow valve, said valve body movable between a firstposition in which fluid communication between said inlet and said firstoutlet is substantially prevented and a second position in which fluidcommunication between said inlet and said first outlet is permitted; avariable-volume control chamber configured to act on said valve body,wherein at a first volume of said control chamber said valve body is insaid first position and at a second volume of said control chamber saidvalve body is moved to said second position; a water level sensorconfigured to sense an above-normal water level in the bowl andcommunicate with said control chamber, wherein said water level sensoris configured to change a pressure within said control chamber to movesaid control chamber from said first volume to said second volume; and afluid passage having a first end and a second end, said first end ventedto the atmosphere and said second end communicating with a water supplypassage connected to the water supply source such that water flowingthrough said water supply passage past said second end tends to drawatmospheric air through said fluid passage, said water level sensorconfigured to selectively substantially block a flow of air through saidfluid passage.
 11. The toilet overflow prevention system of claim 10,wherein said control chamber is in communication with said fluidpassage.
 12. The toilet overflow prevention system of claim 10,additionally comprising a flow restricting orifice within said fluidpassage.
 13. The toilet overflow prevention system of claim 10, whereinsaid overflow valve defines a portion of said fluid passage.
 14. Thetoilet overflow prevention system of claim 10, additionally comprising adiaphragm defining a portion of said control chamber.
 15. The toiletoverflow prevention system of claim 14, wherein said diaphragm carries apush rod, said push rod configured to move said valve body between saidfirst and second positions.
 16. The toilet overflow prevention system ofclaim 10, said control valve additionally comprising a second fluidoutlet in communication with said fluid inlet when said valve body is ineither of said first position and said second position.